CONCHIFERA. 267 



Inclusa (Enclosed), the animals having the margins 

 of the mantle, with the exception of a single opening 

 for the passage of the foot, completely united, so as 



FlG. 203. THE SANDGAPER. 



to form a double tube, the end of which can be pro- 

 truded to a considerable distance from the shell, that 

 gapes more or less widely to give it passage. They 

 almost all of them live buried in the sand, or else 

 they bore into mud or even into the solid rock. To 

 this family belong 



The Razor-shells (Solen)* usually found in the sand, 

 which they penetrate with their powerful foot. They 

 are much valued for their excellence as articles of 

 food. When properly cooked (broiling is the best 

 method), they are by some thought to be superior 

 to any other shell-fish. They lie in their holes 

 nearly in a vertical position, and move up and down 

 in their burrows, sometimes rising to the surface as if 

 to see what is going on in the world above. When 

 the tide goes out they sink deeper. The fishermen 

 then endeavour to tempt them out, as little boys 

 would catch birds if they could, by putting salt on 

 their tails. The salt irritates the extremity of their 

 siphons, and the Solen rises suddenly to get rid of 

 the nuisance. The vigilant human enemy watches 

 the moment, and seizes the opportunity and the 



* <ro>\V solen, a tube. 



N 2' 



